1. Field of the Invention
The present invention relates to a metallic mold for and a method of molding a cavity plate of an ink jet printer head, the cavity plate molded by the same and the ink jet printer head by using the cavity plate.
2. Description of the Related Art
There is an actuator of a head equipped in an ink jet printer, which expands and restores the capacity of many ink storing chambers formed inside the actuator using a piezoelectric element installed corresponding to each of the ink storing chambers, and which applies pressure to the ink inside the ink storing chamber. In this way, the actuator discharges the ink from an ink discharge or nozzle hole formed in each of the ink storing chambers to the external i.e., onto the recording sheet.
As one example of such an actuator, there is an actuator provided with: a cavity plate in which ink storing chambers and ink flow paths to supply the ink to the ink storing chambers are formed; and a nozzle plate which is fixed on the cavity plate and in which fine ink discharge holes are formed.
The cavity plate is produced by injection-molding ceramic such as alumina, and then applying a sintering process to it. In order to uniform the abilities to discharge the ink of all the ink discharge holes, the sizes of the ink storing chambers, the sizes of the ink flow paths and the sizes of the ink discharge holes are uniformed.
However, in the injection-molding process, since a metallic mold is used which is constructed by combining a pin member for forming the ink discharge holes and a corniform member for forming the ink flow paths, a gap is formed between the pin member and the corniform-formed member, resulting in one problem that a burr or flash is generated at the connection portion between these two members when the injection-molding process is finished.
Therefore, the burr or flash is removed by a polishing process. However, the sizes of the burrs or flashes are different from each other at the connection portions between the pin members and the corniform members respectively. Thus, it is difficult to uniform the sizes of the ink storing chambers and the ink flow paths, resulting in another problem that the abilities to discharge the ink of the ink discharge holes cannot be uniformed.